The fierce chair pose

Utkatasana, which is one of the toughest standing asanas, lives up to its name. Also known as the ‘chair pose’ by virtue of its resemblance to a chair, ‘Utkata’ means powerful and fierce. This pose increases strength, balance and stability.
To get into the pose, one stands in Tadasana. Following inhalation, the arms are lifted up in a parallel fashion, the elbows supinated such that the eyes of the elbows face each other. This requires extension of the anterior deltoid muscles. The arms are lifted over the head, besides the ears. This allows muscles in the arms and shoulders to be toned and strengthened. These include the deltoid group, triceps, middle and lower Trapezius Muscles, Rhomboids and Latissimus Dorsi. At the same time, the shoulder blades are firmly retracted and firmed against the back. This enables the thoracic spine to be lengthened. This whole series of movement also involves glenohumeral movement in combination with scapulothoracic movement and thoracic extension.
Following exhalation, the knees are bent to an angle in which the thighs are as parallel to the floor as possible. The inner thighs are kept parallel to each other and the weight of the body is towards the heels. The knees will project out over the feet and the torso will lean slightly forward over the thighs. The tailbone is tucked in towards the pubis to keep the lower back long. To do this, it has to go through an anterior tilt. In this instance, the quadriceps and the adductor muscles are in concentric contraction while the hamstrings and gluteus muscles are in eccentric contraction. As one sinks into the floor, the lower leg muscles will be engaged. These include the tibialis anterior, extensor halluscis longus and extensor digitorum longus. This group of muscles primarily extends the toes and is used for balance and stability.

Utkasana is challenging also because it engages a considerable number of muscles as stabilizers. Within the trunk, there is the abdominal group, the erector spinae. In the hips, there is the gluteus medius and minimus, and the adductor group. The ankles are also engaged in the stabilizing function. While holding the pose, it is important that the lower back maintain its natural slight degree instead of being sunken. The erector muscles contract isometrically to keep the normal curvature of the spine. Such a movement permits breathing through the belly, and enables strength in the lower back to be built up.